Programmable Drop Option
Original Publication Date: 1983-Jul-01
Included in the Prior Art Database: 2005-Feb-07
The ability to selectively drop one or both devices in a two-input NAND elementary logic function, for example, can be useful in mask programmable complex logical functions, such as the multiplexer circuit shown in Fig. 7. For example, it would be useful to be able to selectively eliminate device 2 with its Y input and make a short between the source of device l and the ground potential, in order to allow the designer to hardwire program a value of Y equals one. Alternately, it would be useful for the designer to have the ability to eliminate devices 1 and 2 at the mask level in order to hardwire program a value of Y equals zero for the circuit of Fig. 7. This is accomplished by the programmable drop option invention which is described as follows.